Theists who use the free will response to the problem of evil argue that the existence of moral and natural suffering is unsurprising if God exists. God, they claim, has good reason to create free creatures who play a significant role in shaping their own lives and the lives of others – for good or for ill. Moreover, free will depends on a system of natural laws that enable predictions of the outcomes of one’s behavior; therefore, the suffering that issues from living in such a system becomes inevitable. To sum up, we should not be surprised to find moral and natural suffering in a world created by God.
That’s a summary of the free will response from my previous post. But does this response have any weaknesses? Yes it does. Today I will consider five objections that (if successful) seriously limit the explanatory power and scope of this explanation of evil. As I work through these five, I will also list possible rejoinders which theists could use.
Objection 1: Free will can exist without its misuse
This objection faults the Free Will Theodicy for failing to meet the demands of justice. Justice requires that God allow undeserved suffering only if allowing it (or some other evil equally bad or worse) is the only way to secure an outweighing good. But, so the objection goes, God could have created free agents who do not commit moral evils. God could have created only those creatures whom he knew would always choose good. If God is all-knowing, then he knows which creatures would freely sin and which creatures would not. Free will does involve the possibility of sin, but perhaps some creatures would never realize that possibility. If so, God would know who they are. So why didn’t God simply make those creatures and avoid creating the one’s that would choose to sin? God could do this if he knows what we would do in advance.
Response 1a: Perhaps there are no free creatures who would always choose good.
Perhaps any creature endowed with freedom will decide to choose evil at some point and, if so, none of the worlds feasible for God to create contain free creatures who never do evil. 
Response 1b: There may be very few people who never misuse their freedom.
So had God made a world containing only those types of people, it would be horribly unpopulated, say, containing only five people. Perhaps God prefers a world containing more people capable of relating to him even if it means allowing some of them to do wrong.
Personally, I find it very unlikely that many creatures with significant freedom living together would never go wrong. Plus, such a world would be deficient in other respects (and thus not preferable) because persons would have little or no opportunity to develop virtues like heroism, courage, and compassion in the face of moral threats. So I do not find this first objection convincing.
Objection 2: Horrendous Evil
Other critics claim that some moral evils are too costly to be outweighed by the goods of free will. Just think of the Holocaust. Was preserving the freedom of the S.S. officers worth the systematic slaughter of six million Jews? That seems a bit extreme. The goods of free will might justify allowing some lower grade evils, but examples like the holocaust are too horrendous to be allowed for that purpose. So it seems that for God to be justified in allowing horrendous evil, goods greater than free will must be at stake.
Objection 3: Where is the Compensation?
Consider horrendous evils like child torture. Let us suppose that God allows children to suffer in this way because doing so is the only way to preserve the freedom of their torturers. Let us also suppose that the goods of preserving free will sufficiently outweigh the evils inflicted on these children (I find that idea implausible, but let’s assume it for the sake of argument). Have we thereby found an ethically satisfying explanation of God’s allowance of child torture? Of course not. As I’ve argued elsewhere, the child must be compensated for the wrong. If God is perfectly just, then it’s not enough for Him to simply secure outweighing goods while leaving the child’s suffering uncompensated. But how might God do this?
Perhaps the child is compensated during its short life by the free actions of other benevolent people who showed it love and care. This option is possible, but presumably the love and care it received while alive did not outweigh the horrendous sufferings it endured.
As it stands, the free will response lacks the conceptual resources to explain how child torture is compensated. Of course, if a perfectly just God exists and allows such evils to occur, then he compensates them entirely, but it is unclear to us how this works. Perhaps God ensures that these children enjoy a blessed existence in the afterlife that far outweighs their earthly suffering. But even if that’s true, the free will explanation becomes less simple (and therefore less probable) because it now depends on the truth of additional premises about the reality of post-mortem bliss. Thus, to avoid the charge of tacking on extra premises in an ad hoc way to save the free will hypothesis, the theist will need to show that an afterlife is quite probable on theism, or on other grounds which are friendly to theism.
Objection 4: Different Natural Laws
God could have made a world governed by different natural laws which produce less suffering. Such a world would have been preferable to our own, and so God should have created it instead. Theists have typically responded to the “different natural laws” objection in two ways:
Response 4a: Insufficient Knowledge
We have no idea which alternative natural laws God could have created, and even if we did, we wouldn’t have sufficient knowledge of their effects to gauge whether (on balance) they result in worlds with less suffering than our own. We don’t have enough information to know if a world created with different laws would be better in that way. We can say that all things being equal a world with less natural evil than our own would be a better world, but we have no idea whether things remain equal when natural laws have been tampered with. We just have no idea how the overall balance of goods in a world would be positively or negatively affected if natural laws were altered.
Response 4b: The Anthropic Principle
Also, astrophysicists tell us that very few universes are capable of sustaining life because the values for the constants and variables in their natural laws have to be delicately balanced. Most universes are not life-permitting because they do not fall within the narrow range of physical constants necessary for the existence of creatures like us. An incredible amount of fine-tuning has to occur before a world is hospitable to life, and minor adjustments in the values for those laws prove disastrous. If very few life-permitting universes were available for God to create, then for all we know, some finely-tuned universe(s) like our own had to be created, even if they are somewhat different from ours. And with so few options at God’s disposal, it becomes less likely that natural laws with values different from our own would have been an improvement, viz. resulted in less human and animal suffering. ***Note: this response might conflict with 4(a). ***
Objection 5: Selective, Undetectable Intervention
Even if a universe with natural laws somewhat like our own is necessary for the existence of free, morally responsible creatures like us, God can still reduce the amount of natural evil without adverse consequences. Some divine intervention in the natural order may in fact reduce physical evils without diminishing our ability (or the ability of nonhuman animals) to predict the immediate outcomes of our actions.
For example, God may intervene selectively and undetectably to prevent isolated cases of animal suffering, plagues, and cancer, without making life unpredictable. These interventions would be exceptions to the regular operation of physical laws but would not jeopardize their general character. Defenders of the Free Will response are right to argue that cause and effect relationships would not be predictable if God systematically intervened to prevent natural evil, but their argument has a weakness: the predicable character of the system would remain intact if God selectively intervened in undetectable ways to reduce natural evil. ***Note: How would we know that God is not already doing this?
 Such persons suffer from, what Plantinga calls, “transworld depravity.” While there are possible worlds in which such persons always do good, it is a matter of contingent fact that no actual world in which they exist is one where they always do good. Plantinga’s concept of transworld depravity depends on the theory of “middle knowledge” which implies that God knows all counterfactual truths about what free creatures would do in any circumstance and that God only has the power to actualize a world consistent with that knowledge. Suppose God knew that if he created you in circumstance C, you would choose to do X. Given the truth of that proposition, God cannot create a world with those same circumstances and have you chose non-X, since that would violate your freedom. There is a possible world in which you do non-X, but given what you would actually choose, God cannot create that world.
 A variant of the objection from horrendous evil comes from Ivan in Fyodor Dostoyevsky’s famous novel The Brothers of Karamazov. Ivan blames God for giving us free will because human beings are too feeble and weak to bear the burden of that “gift.” Human freedom is not just any kind of freedom – it is morally significant freedom. It involves (among other things) responsibility for the well-being others; facing complex moral circumstances that hold out devastating consequences for mistakes in judgment; and the capacity to inflict unfathomable evil on others. Ivan’s underlying assumption is that a just God would not endow creatures with responsibilities they cannot be expected to fulfill.
 In light of this objection, Daniel Howard-Snyder admits, “My sense is that we have no idea how God would be justified in permitting the isolated suffering of non-human animals at nature’s hand.” See his “God, Evil, and Suffering.” (2001), p.96.